Screw threads



(No Model. I 5 Sheets-Sheet 1. S. A. DAVIS 83 R. BLAKE.

MACHINE FOR SWAGING SCREW THREADS.

No. 279,353. Patented June 12,1883.

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MACHINE POE SWAGING SCREW THREADS. No. 279,353.

Patented June 12,1883.

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MACHINE FOR SWAGING SCREW THREADS.

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MACHINE FOR SWAGING SCREW THREADS.

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S. A. DAVIS & R. BLAKE. MAOHINE FOR SWAGING SCREW THREADS. No. 279,353. PatentedJune 12.1883.

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UNITED "STATES PATENT OFFICE.

STEPHEN A. DAVIS AND ROBERT BLAKE, or NEWARK, N. J., ASSIGNORS To all whom it may concern:

Be it known that we, STEPHEN A. Dnvrs and ROBERT BLAKE, of Newark, in the county of Essex and State of New Jersey, have invented a new and Improved ScrewiSwaging Machine, of which the following is a description in such full, clear, concise, and exact terms as to enable any one skilled in the arts to which our invention belongs to make and use the same, reference being had to the accompanying drawings, making part of this specification, and to the figures and letters of reference marked thereon.

Figures 1 and 2 of said drawings are verti- I5 callongitudinal sections through said machine,

1 both taken upon the same plane, but showing l the machine set in opposite positions. Figs.

3 and 4 are both top views of the machine,

, but show it set in opposite positions, Fig.

2o 3 corresponding to Fig. 5, and Fig. 4 to Fig.

l 2. Fig. 5 is an elevation of the right-hand end of the machine, showing it in the position it appears in Fig. 2. Figs. 6 and 7 are sevl eral views of thread-swaging dies, hereinafter 1 more fully described.

Our invention consists of an improved screwswaging machine, the construction and operation of which will be readily understood from l the following description, the points of nov 3o elty being designated in the claims concluding this specification. Reference being had to Fig. 2 of the drawi ings, 0 is a screw-shank held by a split chuck, N-, carried by a rotating and reciprocating sleeve,-M, set in a reciprocating head-block, G, operated by a crank-pin, V, set between a pair of crank-wheels, T T, and connected to the head-block by means of the connectingrod S. The split chuck N is made to open and 40 close upon the screw-blank by means of a slot cam, G, in which it is made to move by the motion of the head-block, the chuck being drawn back into the sleeve and upon the blank when the machine is in a position shown by the figure referred to, the cam G- imparting to the chuck a motion endwise, by which it is thrust out and drawn back into the sleeve by the reciprocating motion of the head-block C. To give the sleeve M a rotating motion, cOgS M are cut in its periphery, into which the cog-wheel A gears, the cogs in the sleeve be- TO THE SUPERIOR DRIVE SCREW COMPANY, OF NEW YORK, N. Y.

MACHINE FOR SWAGING SC REW-TH READS.

SPEQIFIGATION forming part of Letters Patent No. 279,353, dated June 12, 1883.

' Application filed May 11,1882. (No model.)

- ing made in length equal to the width of the wheel A, plus the distance the sleeve is to travel endwise. The reciprocating or endwise motion of the sleeve is obtained by means of a screw-thread, K, cut on its rear end, and made to screw into a corresponding thread cut in the head-block O, the sleeve being thus made to move endwise at the same time it is made to rotate about its own axis. Therotary motion of the sleeve M is transmitted from a cog-rack, Gr, bolted to the frame of the machine, and into which gears a pinion-wheel, E, upon the end of the shaft B, upon which the wheel A- is also fixed, and which has its journal-bearing in the headblock G, by which it is carried. By these means it will be seen that by the motion of the crank V the headblock G will be given a reciprocating motion, the pinion E a reciprocatingand rotary motion in the cog-rack G,which motion will also be imparted to the wheel A, which will in its turn impart a rotary motion and an endwise motion to. the sleeve M at the same time it is reciprocating with the head-block. These several parts and motions being understood, assume the screw-blank to be clamped in the potion shownby Fig. 2. The head-block, as it is moved forward by the crank V, will carry the screw-blank over the long stationary swaging-die Q, and at the same time the blank will be rotated by the cog-wheel. A and moveback endwise by the screw-thread K, or other device adjusted. to give the desired pitch to the thread to be cut in the screw-blank.

Having thus provided for holding the screwblank, and giving it the proper motion over the stationary swagingdie Q, we make a corresponding die, Q, and set it into aslide-bearing exactly opposite the die Q, as shown in 5, adjusting the cutting-edges of the two dies at a proper angle in relation to each other to form the desired thread on the screw.

Having thus made and adjusted the die Q,

we impart to it a reciprocating motion over the die Q by means of .a crank, l", set in a crank-wheel, T, and a connecting-rod, S, causing the die Q to travel far enough each way over the die Q to clear the dischargeholes B, through which the screw drops when it is discharged out of the clamp N.

Now let the machine be in the position shown by Fig. 2, and let the head-block move forward, carrying the screw-blank over the die Q. The die Q will also move forward upon the screw-blank, compressing it between the two dies and swaging the thread on it by the pressure of the dies and the motion of the screw blank, the finished screw being discharged, when it reaches the opposite end of the die Q, by the cam G, the chuck N being then thrust forward in the position shown by Fig. 1, allowing the clamp to spring open and release the screw. As soon as the screw is discharged the headblock commences its return motion, a succeeding blank drops in place, and the operation is repeated ad infinitmn.

In the operation above described it will be observed that the chuck N moves back. endwise with the sleeve, and is thus made to retain the blank, notwithstanding the endwise motion of the sleeve, the sleeve and chuck moving together untilthe thread is formed, the cam then throwing the chuck forward and releasing the screw. The arrangement for feeding the screw-blanks in the clamp is not shown in the drawings, as it forms no part of the invention making the subject-matter of this-specification. It is proper to add, however, that the slot-cam G is cut in two long stationary blocks, set far enough apart to allow the body J of the chuck to travel between them, the head L of the chuck only traveling into-the grooves forming the cam, thus leaving the upper end of the chuck always open to receive the screw-blanks.

By Figs. 6 and 7 of thedrawings are shown the dies in detail, which may be made in the form shown or of such other form as may be required to carry out the purpose of the in vention.

In concluding this specification, weobserve that the invention is quite as applicable to the manufacture of screw-bolts as to wood-screws, and we intend to embrace in the following claims the above-described machine for making the thread on all sorts of metal screws. The features that distinguish this screw-swaging machine from all others of its class are found in the fact that the thread is swaged between the top and bottom die, each of which has a single edge corresponding with the form of the thread, both dies being set on the same plane, and the pitch of thread i being formed by the mechanism that carries the screw-blank. In this machine only one convolution of the thread is cut at each revolution of the screwblank, and the pitch of that convolution is not formed bythe dies, but by the machinery that carries the blank. The blank has a rotating and a lateral movement independent of the dies that swage the thread and that govern the formation of the thread.

The chuck that carries the screw-blank may of course be modified in a variety of ways. Thus, for example, instead of making the clamp open when pushed forward by a cam,

one may be employed which is forced back by y a spring as soon as it reaches the end of the die, thus instantly releasing the screw.

Having thus described our invention, we claim 1. In a screw-swaging machine, two threadswaging dies, one moving opposite the other, and each having a single edge, by which a crease is swaged inthe blank, in combina tion with a blank-chuck having a rotating and a lateral endwisemotion, by which the crease is made in the form of ahelix or scrow-thrcad 011 the blank. Y

2. In a screw-swaging machine, the combination of a reciprocating head-block, C, a chuck, X, a chuck-sleeve, M, and a chuckcam, G, the several parts coacting substantially as described.

3. In a screw-swaging machine, the C0111- bination of a reciprocating head-block, O, a clamping device, N, for the screw-blank, and a stationary cam, G, to operate the clamping device, substantially as described.

4. In a screw-swaging machine, the combination of a stationary cog-rack, G, a stationary cam, G, areciprocating head-block, (7, carrying a clamping-chuck, N, and a cog and pinion wheel, A E, the several parts to acting substantially as described.

STEPHE\ A. DAVIS. ROBT. BLAKE.

Vitn esscs:

ROBT. ELDER, ISAAC A. Kine. 

